DE2255498C2 - Process for the production of a catalyst for the dehydrogenation of saturated to correspondingly unsaturated hydrocarbons - Google Patents

Description

The invention relates to a process for producing a catalyst by incorporating at least one metal from group VI A or VII A of the periodic table, which can be molybdenum, tungsten or rhenium, and from at least one metal from group III B, IV B and VB of the periodic system, which can be gallium, indium, thallium, germanium, tin, lead, antimony or bismuth. In an aluminum carrier by applying the metals to the aluminum oxide, then drying, calcining and optionally reducing at a temperature of 350 to 700 ° C under a stream of hydrogen, the catalyst having a specific surface area of about 20 to 150 mVg, preferably 40 to 80 m ² / g possesses.

The catalyst is especially suitable for dehydrating saturated to corresponding unsaturated hydrocarbons with the same number of carbon atoms in the molecule.

A very important use of the present invention is in the dehydrogenation of the straight chain paraffinic hydrocarbons with 3 to 40 carbon atoms. The products of the dehydrogenation of the straight-chain hydrocarbons represent a Remarkable raw material for the production of chemical compounds of the sulphonate type or sulfates of alkyl aromatic compounds which are susceptible to biodegradation.

Another important use of the present invention is in the products of dehydration to separate them and then by OXO synthesis in langkeitlge To convert alcohols.

Another use of the invention is Dehydrogenation of the naphthenic hydrocarbons containing 3 to 40 carbons per molecule, And in particular of naphthenic hydrocarbons with 5, 6, 7 or 8 chain links; during dehydration of these latter hydrocarbons are the naph » thene almost entirely to aromatic hydrocarbons Converted.

It is known that the saturated hydrocarbons by catalytic dehydrogenation into unsaturated hydrocarbons can be converted. A variety of methods and catalysts are used for dehydrogenation of η-paraffins have been used for the purpose of obtaining corresponding olefins. A typical one Example is the dehydrogenation of η-butane in butene, and by means of a catalyst consisting of chromium oxide on aluminum oxide. Suggested by the others Catalysts are those made of precious metals such as platinum and palladium on a carrier such as aluminum oxide, Called silicon oxide or combinations thereof.

In DE-AS 20 32 495 is an acidic catalyst described, which contains platinum, rhenium, germanium and a surface area of 100 to 500 mVg, preferably 175 mVg.

US Pat. No. 3,584,060 describes a dehydrogenation catalyst composed of a platinum group element, rhenium and tin on a porous carrier, preferably with alkali and alkaline earth metal to neutralize the acidic character.

in US-PS 3,157,510 is a Hydrierurigskaiaiysaior which contains rhenium, germanium and an element of Group VIII of the periodic table.

Investigation of these catalysts used in known processes has shown excessive formation of carbon or coke and a rapid decrease in the activity of the catalyst. In addition, these catalysts lead to disruptive side reactions such as cracking, aromatization, isomerization of the skeleton and the formation of polyunsaturated hydrocarbons such as dienes and trlene. Since the desired product is generally a monoethylene hydrocarbon, these side reactions reduce the effectiveness of the processes, so that these processes and the catalysts used prove to be of little economic interest.
In contrast, the present invention is based on the tasks

- to create a catalyst for a process for the dehydrogenation of saturated hydrocarbons, the undesirable side reactions such as cracking, aromatization and isomerization To be reduced to a very considerable extent,

- A catalyst for a process for dehydrogenation from saturated hydrocarbons to monoätvienlschen hydrocarbons, and with a minimal conversion to polyethylene Hydrocarbons,

- To create a catalyst for a process with .1 »nen the saturated hydrocarbons at a minimum Koksblldu.ig and maintaining a long-lasting, very high catalyst activity can be dehydrogenated

According to the invention, this object is achieved with a method of the type mentioned above solved in that the Neutrallsatlonswärme of the aluminum oxide Less than 10 calories per gram of catalyst due to ammonia adsorption! 320 "C and a pressure of Has 3OC mm of mercury.

The acidity of the catalyst is reduced by the known ammonia adsorption test determines how he e.g. in the "Journal of Catalysis, 2, 211-22 (1963)" is described. The method is that the Catalyst is heated under vacuum (0.01 mm mercury) to 600 ° C until it is completely degassed (haupU to the water and the unwanted venin *

remedies to remove); then you give the catalyst at 320 ° C In a calorimeter, ammonia adds in an amount that the pressure of the system eventually increases 300 mm of mercury and measures the amount that has been released Amount of heat.

The catalyst must therefore have a heat of neutralization due to ammonia adsorption which is less than about 10 calories per gram of catalyst at 320 ° C and a pressure of 300 mm of mercury (the heat of neutralization in the aluminum oxide used as a carrier is practically the same, i.e. it is less than 10 calories per gram of catalyst). The catalyst must also have a specific surface area of about 20 to 150 mVg, preferably between about 40 and 80 mVg; the pore volume of the catalyst Hegt z. B. between about 0.4 and 0.8 cmVg, with at least 75% of the porosity pores of _o correspond to a mean diameter between 100 and 500 Å. (The specific surface and the pore volume of the aluminum oxide used as a carrier are therefore practically the same as the values mentioned above.)

The Aiurniniutriüjiidariums that are used as carriers are not all equivalent, and it is preferable to use • / -Aluminum oxide beads (e.g. the tetragonal y-aluminum oxide). But you can too other alumina agglomerates such as extrudates or Use tiles that meet the aforementioned conditions.

If the acidity of the alumina support is found to be too strong, it can be reduced by adding certain basic compounds before or after adding the dehydrating elements or compounds which can decompose under the reaction conditions and thereby give basic compounds. Examples of such compounds are the oxides and hydroxides of alkali or alkaline earth metals and the carbonates and other salts of weak acids (dissociation constant preferably below 10 ³ ) of the same metals, e.g. B. soda, potassium, sodium carbonate, potassium carbonate, calcium acetate, sodium nitrate or magnesium acetate. It is generally not necessary to add more than 2% or even more than 1% basic compound (by weight in relation to the catalyst).

The total content of metal in groups VI A and VII A, given in weight in relation to the catalyst, is between 0.01 and 1% and preferably between 0.1 and 0.5 * .. that of elements of the groups III B, IV B and V B is between 0.1 and 1% and preferably between 0.1 and 0.5%, and that of the elements of group VIII, if available, is between 0.01 and 1 *

The dehydrating elements (metals of groups VI A, VII A and elements of groups III B. IV B, V B) can be applied separately or simultaneously to the carrier, namely in the form of solutions, In which they are included, e.g. B. of ammonium, sodium or Callum meta- or para-tungstate, from Ammonium, sodium or potassium para-molybdate. of perrhenlumic acid. Ammonium, sodium or potassium perrhenate, Gallium, indium, thallium, germanium, tin, lead, antimony and bismuth nitrate, chlorld and * oxalal,

After the dehydrating elements have been applied to the support, the catalyst is dried by heating In an oxidizing atmosphere at a temperature of e.g. B. 300 to 600 "C, then for 2 to 30 Hours Under a stream of hydrogen at a temperature of e.g. B. 350 to 700 ° C reduced, namely at an hourly hydrogen throughput in the order of 100 to 10000 times the catalyst volume. This last operation is preferably carried out in the dehydration reaction vessel. One can do the caIzination also omit and carry out the reduction directly.

The conditions of use of these catalysts are not indifferent. To achieve an acceptable degree of lim conversion must be the temperature in the dehydrogenation of straight-chain paraffinic hydrocarbons Between 300 and 600 ° C and preferably between 400 and 500 ° C, with hourly volume flow rates of liquid saturated hydrocarbons in the order of magnitude 0.1 to 30 times and preferably 2 Lis 10 times the catalyst volume and at absolute Pressures from 0.1 to 20 bar and preferably from 1 to 5 bar. The hydrogen partial pressure is high Importance for the stability of these catalysts; the molar ratio hydrogen / hydrocarbons at the entrance of the resection vessel can be between 0.1 and 30 and between 2 and 20 and preferably between 8 and 15. In order to achieve good degrees of conversion, the temperature during the dehydrogenation must cyclic hydrocarbons between 300 and 600 ° C and preferably between 500 and 600 ° C Hegen, at hourly volume flow rates of liquid hydrocarbons in the order of 0.1 to 20 times and expediently 2 to 10 times the Catalyst volume and at absolute pressures from 1 to 60 bar and preferably from 5 to 40 bar. The Hydrogen partial pressure Is of great importance for the stability of these catalysts: the molar ratio hydrogen / hydrocarbons at the entrance of the reaction vessel can be between 0.5 and 30 and advantageously between 2 and 10. As examples of dehydrable Hydrocarbons selenium in addition to the fractions of propane containing hydrocarbon mixtures, the n-butane, isobutane, isopentane, η-hexane, n-heptane, n-dodecane, n-hexadokine. the cyclopentane, called the cyclohexane, the cycloheptane, the cyclooctane and the methylcyclopentane.

The following examples serve to illustrate the present invention.

Example I.

A fraction of normal Cin-C ^ -hydrocarbons is brought into contact in a dehydration reaction vessel made of steel, the inner diameter of which is 2 cm and the length of which is 40 cm, with a catalyst A, made of rhenium and tin on γ-aluminum oxide spheres. This catalyst is made by impregnating; -Aluminum oxide spheres with a specific surface area of 69 mVg and a pore volume of 58 cm 'per 100 g have been produced (75% of this pore volume corresponds to pores with a smooth mean diameter between 100 and 500 Å). The result Neutrallsatlonswärme Ammonlakadsorptlon was 7 calories per gram in this y alumina. Impregnating initially 100 g of this 58 cm Aluminlumoxldkügelchen mlv ¹ of an aqueous solution containing 20.4 cm 'of a 0.98 wt,% * rhenium containing Perrhenlumsäurelö' includes Sueng. After impregnation and drying, 0.3il g of Zlnn-II-Chlorld is added to 2 molecules of water. After 3 hours of contact, the aluminum oxide * spheres have completely absorbed the solution. It is dried for 6 hours at 100 ° C. in a drying cabinet and then calcined for 2 hours at 400 ° C. under a stream of air, then

For 2 hours at 500 ° C. After cooling down, the Put the catalyst into the dehydration reaction vessel, where he in about 12 hours at 530 ° C in a stream of hydrogen is reduced by 50 I per hour.

The catalyst obtained in this way contains 0.2% by weight of rhenium and 0.2% by weight of tin; its heat of neutralization due Ämmcniakadsorption amounts to 7 calories per gram, its specific surface area 62 m ² / g and its pore volume 54 ^cm3 / 100 g.

Manage ', the C _{1 ( rC H} fraction on a catalyst, with a space velocity of 2 liquid volumes per volume of catalyst and per hour, at a temperature of 470 ° C, an absolute pressure of 1.5 bar and with a Molar ratio hydrogen / C _ia -C | ₄ fraction of 10 at the entrance of the reactor

Table I.

clay vessel. Then one analyzes the one from the reaction vessel outflowing liquid and gaseous products as a function of time, by Brorn number, Cttro? natographle. In gas phase, mass spectrometry and magnetic Nuclear magnetic resonance measurement: The results are given in Table I.

Example 2

Using the method of Example 1, five catalysts A, A ₂ , A ₃ , A ₄ and A _{5 are} prepared, their heat of neutralization due to ammonia adsorption about 7 calories per gram, their specific surface area about 62 m ² / g and their pore volume about 54 cmV100g and their composition (in parts by weight) is the following:

Kataly age of Catal Composition of the liquid product n-mono Isooieflne Diols Aro % of the cracked sator tors In (In% by weight) olefine + Iso- fine mate Batch at C] - to hours n-paraf paraffine Cj coal water f! ne 15.7 0.3 0.1 0.5 serstrTin 4th 14th 0.2 0.1 0.3 A. 50 83.3 13.3 0.2 0.1 0.2 0.1 200 85.3 12.5 0.1 - 0.2 0.1 400 86.1 26.2 0.7 0.6 2.5 0.1 4th 87.1 25.5 0.6 0.5 2.4 0.1 Ai 50 69.7 24.3 0.6 0.5 2.1 0.3 200 70.7 23.7 0.5 0.4 2 0.3 400 72.2 28.9 0.9 0.7 3.3 0.3 4th 73.2 28.1 0.8 0.7 3.1 0.2 50 65.9 26.9 0.7 0.6 2.7 0.3 200 67 26.2 0.7 0.6 2.5- 0.3 400 68.8 28.2 0.8 0.7 3.1 0.3 4th 69.7 27.4 0.8 0.6 2.9 0.3 A ₃ 50 66.9 26.2 0.7 0.6 2.5 0.3 200 68 25.6 0.6 0.5 2.4 0.3 400 69.7 27 0. ° 0.6 2.8 0.3 4th 70.6 26.2 0.7 0.6 2.5 0.3 A ₄ 50 68.5 25th 0.6 0.5 2.3 0.3 200 69.7 24.5 0.6 0.5 2.1 0.3 400 71.3 23.6 0.6 0.4 1.9 0.3 4th 72 23 0.5 0.4 1.8 0.3 As 50 73.3 21.8 0.4 0.4 1.5 0.2 200 74.1 21 0.4 0.3 1.4 0.2 400 75.7 15.6 0.2 0.1 0.5 0.2 4th 76.7 9.1 0.2 _ - 0.2 B. 50 83.5 42 0.1 _ - 0.1 2u0 90.7 3 - - - - 400 95.7 - 0.2% rhenium 97 gallium - A. 0.2% rhenium Germanium A ₂ 0.2% rhenium and 0.2% Indium A, 0.2% rhenium and 0.2% antimony A ₄ 0.2% rhenium and 0.2% A, 0.2% platinum and 0.2% B.

The example carried out with catalyst A is given for the sake of comparison and does not belong to the present one Invention.

One has the Cig-C ^ 'FrakMon on these catalysts of Example 1 under the same implementation conditions. The results are shown in Table I.

In addition, one has the io ^ for comparison
Flon from example 1 under the same conditions of this example also passed on to a conventional catalyst B containing aluminum oxide and 0.296 platinum enU. The catalyst B was prepared by a method similar to that of Example 1, with instead

of the perrhenlumic acid 58 cm ^{3 of} an aqueous solution containing 7.7 cm ^{3 of} a hexachloroplatinic acid solution with 2.6% by weight of platinum were used. The catalyst B has a specific surface area of 62 m ² / g, a pore volume of 54 cm / 50 g, and if it is neutrals, the heat due to ammonia adsorption is calories per gram.

These results show that it is advantageous, the rhenium, a metal of the groups JÜ _B; IV B and VB to be added: The activity and stability of such catalysts are significantly better than when the catalyst contains only rhenium (catalyst A) or only platinum (catalyst B).

Example 3

Proceed as in Example 1 and provide catalysts C, Cj, C ₂ , D, D ₁ , D ₂ , E, E | and Ej her, whose neutral heat of ammonia due to ammonia adsorption is about 7 calories per gram, whose specific surface area is 65? ³ / g-, animal pore volume is 54 cmV100 g and whose composition (in weight cells) is the following:

0.2% iridium - 0.295 molybdenum 0.2% iridium - 0.2% molybdenum - 0.2% thallium 0.2% iridium - 0.2% molybdenum - 0.2% indium

0.2% palladium - 0.2% rhenium 0.2% palladium - 0.2% rhenium - 0.2% germanium
0.2% palladium - 0.2% rhenium - 0.2% tin

0.2% platinum - 0.2% tungsten

0.2% platinum - 0.2% tungsten - 0.2% gallium 0.2% platinum - 0.2% tungsten - 0.2% antimony

Table II

The catalysts C, C |, C ₃ , O, D _f , D ₁ were reduced at a temperature of 50 ° C, the catalysts E, E, and E ₂ at 560 ° C.

These 9 catalysts were used for dehydrogenation the Cio-Cu-Fakllon of Example 1 under the lh example 1 is used.

Those carried out with catalysts C, D and E. Examples do not belong to the invention and are given by way of comparison. The results are shown in Table II.

The results in Table II show first of all how important it can be to use a metal! the Πηιηηβ VIII zii7uset7en: The catalysts C. and C ₂ (Table II), one of which contains palladium, rhenium and germanium, the other palladium, rhenium and tin, both give better results than the catalysts A ₁ and A) (Table I), which contain rhenium and germanium or rhenium and tin. The results of Table II also show that the catalysts which simultaneously contain a Group VIII metal, a Group VI A or VII A metal and a Group III B, I "- 'B or VB metal are better than that Catalysts containing the following metals:

Kataly Age of Composition of liquid product Diols Aro % of the cracked sator Catal (In weight-K) fine mate Batch to Cy tors In n-paraf- n-mono- Isoolefine up to C ₅ -carbons- hours flne olefine + Iso- hydrogen parafflne

C ₁

D ₁

D,

50
200
400

50

200

400

50

200

400

50

200

400

50

200

400

50

200

400

50

200

400

80
84.6 88.3 89.9

56.5 59.6 64.6 66.7

59.9 63.3 68.5 71.1

69.5 74.2 79.4 81.8

50.1 53.6 59
60.9

59.6 63
68.5 71.4

74.7 78.7 83
85.6

18.3 14.6 11.5 10

35.4 33.2 29.8 28.4

33 30.7 27 25.2

26.3 22.9 18.9 17

39.6 373 33.7 32.4

33.2 30.9 27 25

22.5 19.4 16 13.8

0.4 0.2 0.1 0.1

1.3 1.2 0.9 0.8

1.2 I.

0.8 0.6

0.7 0.5 03

0.2

U 1.5 U 1.1

1.2 1

0.8 0.6

do

0.2 0.1 0.2
0.1

1.1
I.

0.8
0.7

0.8
0.6
0.5

0.6
0.4
0.2
Ό, 2

1.4
1.2
1
0.9

0.8
0.6
04

0.4
03
0.1
0.1

0.9
0.4
0.1

5.3
4.6
3.5
3.1

4.5
3.8
2.8
2.3

2.6
1.8
I.
0.7

6.7
5.9
4.7
43

4.6
3.9
2.8
2.2

1.7

0.6
0.3

0.2 0.1

0.4 0.4 0.4 0.3

0.4 0.4 0.3 0.3

0.3 0.2 0.2 0.1

04 0.4 0.4

0.4 0.4 03 03

0.2 0.2 0.1 O.I

still table II Age of 22nd n-mono 55 498 Diols Era* 10 Kataly Catal olefine fine mate salor tors In % of the cracked 9 hours Composition of 27.6 0.7 2.9 Batch at C ₁ - (In weight »«) 25.1 0.5 2.3 to (^ coals 4th n-paraf 21.1 0.3 1.4 hydrogen E ₁ 50 fine 19.1 liquid product 0.2 1 200 37.7 1.3 6.1 0.3 400 66.7 35.2 Isoolefine 1.1 5.2 0.3 4th 71.2 31 + Isö- 0.9 3.9 0.2 E ₂ 50 76.6 28.8 parafflne 0.7 i, 3 0.2 200 79.2 0.8 0.5 400 52.9 0.6 0.4 56.8 0.4 0.4 62.8 0.3 0.3 66 1.5 1.3 1 0.9

- Either only one metal from group VIII (see, for example, the _{results obtained with the catalysts Ci, C 2} , D |, D ₂ , E | and E ₂ and the results obtained with the catalyst B of Table I)

- or noodles metal of group VI A or VI A (cf. the results obtained with the catalysts C ₁ , C ₂ , D, D ₃ , E | and E ₂ and the results obtained with the catalyst A of Table I, for example )

- Or a metal from group VIII and a metal from groups VI A or VII A (cf., for example, those with catalysts C |. C ₂ , D |, D ₂ , Ei and E ₂ and those with catalysts Ci , D and E obtained).

Examples 4 and 5

Ulese examples are given for comparison and do not belong within the scope of the present invention.

The procedure is as in Example 1 and a catalyst is provided Dj her, the 0.2 wt .-% platinum, Contains 0.2 wt% tungsten and 0.2 wt% gallium.

The support of this catalyst consists of ε-aluminum oxide with a specific surface area of 230 m ² / g and a total pore volume of 0.57 cmVg. (84SS of this pore volume correspond to pores with an average diameter of 50 to 150 Å). The neutral ion heat due to ammonia adsorption was 15 calories per gram for this alumina.This catalyst was reduced in a hydrogen syrup at a temperature of 530 ° C. The catalyst had a neutral temperature due to ammonia adsorption of 15 calories per gram, its specific surface area was 215 mVg and its pore volume was 0.55 cmVg.

Using the procedure of Example 1, a catalyst D _{4 is} prepared having 0.2 wt.% Platinum, 0.2 wt.% Tungsten, and 0.2 wt.% Gallium. The support of this catalyst consists of aluminum oxide in the transition state with a specific surface of 130 mVg and a total pore volume of 0.95 cm ³ / g. The catalyst D ₄ was reduced in a stream of hydrogen at a temperature of 530 ° C. It had a neutral temperature due to ammonia adsorption of 12 calories per gram, its specific surface area was 120 mVg and its pore volume was 0.90 cmVg. The Cio-C ₁₄ fraction from Example 1 is passed onto these catalysts D ₃ and D _4.

The reaction conditions are those of Example 1. The performance of these catalysts D ₃ and D ₄ , compared with that of catalyst D 1 of Example 6 are given in Table III.

Tabel III Composition of n-mono liquid product Ct Diols Aro % of the cracked Kataly Age of (In wt. 5S) olefine fine mate Batch of ci- sator Catal n-paraf Isoolefine bls Cs carbon tors In flne 39.6 + Iso- 1.4 6.7 hydrogen hours 37.3 parafflne 1.2 5.9 50.1 33.7 1.7 1 4.7 0.5 D, 4th 53.6 32.4 1.5 0.9 4.3 0.5 50 59 41.3 1.2 3.2 19.1 0.4 200 60.9 39.1 2.9 17.1 0.4 400 31.1 34.3 4.? 2.1 12.8 1 D ₃ 4th 36.2 32.9 3.8 U9 11.6 0.9 50 47.3 38.1 2.7 2.7 16.2 0.8 200 50.4 35.9 2.4 2.4 14.2 0.8 400 38.6 31.1 3.6 1.8 9.3 0.8 D ₄ 4th 43.7 29.7 3.1 1.6 8.3 0.7 50 54.8 2.3 0.7 200 57.9 1.9 0.6 400 Example 6 \ e? aninniifin

apparently. In order to avoid a severe decrease in selectivity, one must use a carrier of low acidity use whose Nesitrslisatioriswärme due to ammonia adsorption below 10 calories per gram

This example does not belong to the invention.
The procedure is as in Example 1 and using the ° -AliimlnliimnYlritr3gp.rg YOQ Example 4 three catalysts D ₅ , D ₆ and D _{7 of} the following composition (in parts by weight) animal

12th

0.2% platinum, 0.2% tungsten, 0.2% gallium,
1% lithium

0.2% platinum, 0.2% tungsten, 0.2% gallium,
1% sodium

0.2% platinum, 0.2% tungsten, 0.2% gallium,
1% potassium

The catalysts D ₅ , D ₆ and D ₇ have a heat of neutralization due to ammonia adsorption of

10 calories per gram, a specific surface area of about 215 rnVg <md a pore volume of about 0.55 cmVg.

The reduction temperature of these three catalysts was 530 ° C. The C _{l (r} C, 4-factor from Example 1) was passed onto these three catalysts.

The implementation conditions are those of Example 1, the results are shown in Table IV.

Tabel IV Composition of n-mono liquid product Diols Aro % of the cracked Kataly Age of (In weight · «) oleflne fine mate Batch of C | · sator Catal n-paraf lsooleflne to Cs carbon tors In flne 40.8 + Iso 2.1 12.4 waterless hours 38.5 paraffine 1.9 H 41.5 33.9 2.5 » / *
I. J P.4 0.7 D ₅ 4th 45.7 32.3 2.2 1.3 7.5 0.7 50 53.9 39.7 * **
I, ' 2.5 14.6 0.6 • \ Λ / ν
ZUU 56.9 37.5 1.5 2.2 12.9 0.5 400 39.4 32.8 3 1.7 9.7 0.8 D ₆ 4th 44 31.1 2.6 1.5 8.5 0.8 50 53.2 39.2 1.9 2.7 15.3 0.7 200 56.6 36.9 1.7 2.3 13 5 0.6 400 38.8 32.3 3.1 1.8 10 0.9 D ₇ 4th 43.8 30.7 2.7 1.6 8.9 0.8 50 53.3 1.9 0.7 200 56.5 1.7 0.6 400

One can reduce the acidity of acidic carriers by adding them of alkaline elements. This increases the selectivity of the catalysts. However, the results are well below those obtained with carriers made from the start j were weakly angry, d. H. with carriers according to the invention.

Example 7

One wants to dehydrate a gasoline from steam cracking. The batch has the inferred composition (In Parts by weight):

Aromatics 74.4%

Naphthenes 16.6%

Paraffins 9%

The main features were the following:

as large as the catalyst volume, and the molar ratio Hydrogen / batch is 5.

The results are shown in Table V.

Table V Composition of the Product (In the reaction vessel catalyst exiting Naphthenes Wt .-%) Aromatics 1.8 Paraffins 86.7 0.7 11.5 A. 88.1 0.2 11.2 A ₁ 88.5 0.4 11.3 A ₂ 88.2 0.9 11.4 A ₃ 88 11.1 A ₆

Bromine number
Content of maleic anhydride
Potential Gummlanteli
Distillation ASTM

Starting point

End point
Total sulfur content

0.2

52 ° C
151 ° C
2 ppm by weight

This batch of hydrogen is passed through a reaction vessel at an average temperature of 560 ° C., inlet temperature 580 ° C., outlet temperature 530 ° C.). The catalysts A, Ai, A ₂ and A _{3 of Examples 1 and 2 and a catalyst A 6} prepared by the method of Example 1 and containing 0.2% rhenium and 0.2% thallium, whose heat of neutrality is due to ammonia adsorption, are used 7 calories per gram, the specific surface of which is about 62 m ² / g and the pore volume of which is about 54 cmV100g. The pressure is 15 Ba ?, the hourly volume throughput of the batch is twice that

Example 8

Using the method of Example 1, four catalysts F, F |, G and G _{1 are} prepared whose neutral heat of air due to ammonia adsorption is about 7 calories per gram, whose specific surface area is about 62 m ² / g and whose pore volume is about 54 cmV100 g whose composition (in parts by weight) is the following:

F.
F,
G

0.2% molybdenum

0.2% molybdenum and 0.2% gallium

0.2% tungsten

0.2% tungsten and 0.2% germanium

_{The C 10} -Ci4 fraction from Example 1 was passed onto these catalysts, under the same reaction conditions. The results are shown in Table VI.

In the context of the present disclosure, the term “calorie” includes the so-called gram calorie, too called small calorie, understand.

13th VI 22 55 498 n-mono isooleflne Diols 14th Aro % of the cracked Age of oiledne + Iso- fine mate Batch of ci- Tabel Catal parafflne bls Cs-Kohl- Kataly tors in 12.3 0.3 0.1 0.1 hydrogen sator hours 4.1 0.1 0.1 0.1 1.1 0.1 - - o.t 4th Composition of the liquid product 0.6 - - - o! i 50 (In weight *) 24.9 0.5 0.5 2.4 - F. 200 n-paraf 22.4 0.6 0.4 1.7 - 400 flrie 18.1 0.2 0.1 1.0 0.2 4th 15.1 0.2 0.1 0.5 0.1 50 87.1 14.0 0.2 0.1 0.4 0.1 f, 200 95.5 12.8 0.1 0.1 0.2 0.1 400 98.8 10.7 0.1 - 0.1 0.1 4th 99.4 S, 2 - - 0.1 50 71.5 27.2 0.7 0.7 2.8 - c; . 200 74.8 24.6 0.6 0.5 2.2 - 4üu 80.5 20.3 0.5 0.3 1.4 0.2 4th 84.0 18.1 0.2 0.2 1.1 0.3 50 85.6 0.1 C ₁ 200 86.7 0.1 400 89.1 9i, p 68.4 71.8 77.4 80.3

Claims (1)

Claim: I. Process for the preparation of a catalyst for Dehydrogenation of saturated to correspondingly unsaturated hydrocarbons by incorporating at least one metal from group VI A or VII A of the periodic table, which is molybdenum, tungsten or rhenium, and of at least one metal from group HIB, IVB and V 3 des periodic system, which is gallium, indium, thallium, germanium, tin, lead, or antimony Bismuth can be, optionally with a platinum group metal, in an alumina support by application the metals on the aluminum oxide, subsequent drying, calcining and, if necessary, reducing at a temperature of 350 to 700 ° C under a stream of hydrogen, the catalyst being a specific Surface of about 20 to 150 mVg, preferably 40 to 80 mVg, thereby characterized in that the heat of neutralization of the alumina is due to ammonia adsorption less than 10 calories per gram of catalyst at 320 ° C and a pressure of 300 mm of mercury Has.